the bad part (about 70% of Boscombe) is? Did you never walk up Sea Road?

Basically, once you get to Argyll Road it gets 'interesting'. Within the past year there have been two murders in Roumelia Lane alone (1 x stabbing and 1 x drug dealer shot in the face), there's also been another fatal stabbing in The Crescent and a guy was hacked to death in a flat on Cecil Road, then buried in a shallow grave in Poole. Broadly Argyll Road, Cecil Road and all points North heading towards The Crescent, then beyond that to Carysfort Road and the red light district is the poorest urban area in the South West of England.

I'm aware of the shooting that occured recently but our flat was in a reasonably well off portion of the place.
Aside from FACTS about drugdens and overpopulated housing filled with angry eastern europeans and chavs, I didn't get any worse vibes from the place than anywhere else in Bournemouth. It's like some kind of suburban nightmare sprawl in general.
Maybe I'm just gleefully naive.